Disclosed herein are core-shell polymer nanoparticles and a method for making emulsion aggregation toner particles using these nano-sized particles. The core-shell polymer nanoparticles have a core portion that may comprise a crystalline component and a shell portion having an amorphous component, where the amorphous component and crystalline component are substantially incompatible.
The nano-sized core-shell particles may be used as starting particles in an emulsion aggregation process, and may be aggregated with another amorphous resin particle, which may be compatible with either or both the amorphous and crystalline resins of the core-shell nanoparticles, in generating emulsion aggregation toner particles.
The nano-sized particles are advantageous in permitting inclusion of greater amounts of crystalline materials, thereby lowering the minimum fixing temperature of the end toner particles.